Cooling tube included in aircraft heat exchanger

ABSTRACT

A channel tube includes a body having first and second surfaces extending between first and second opposing ends to define a tube width. The first and second surfaces are separated from each other by a distance defining a tube height. A plurality of ports extend through the body and between the first and second surfaces to define a fluid path extending in a direction of the tube width. Each port defines a plurality of walls and a plurality of ribs having a thermal conductive surface to transfer heat therethrough. A first wall extends in a direction of the tube width. The second wall extends in a direction of the tube width and is disposed opposite the first wall. At least one rib is integrally formed between the first and second walls and extends perpendicular thereto.

BACKGROUND

The present inventive concept relates generally to a heat exchanger, and more particularly, to a cooling tube included in a jet aircraft heat exchanger.

Commercial jet aircrafts typically include a one or more galley areas having one or more cooling compartments where food and beverages are stored. The cooling compartments include cooling units to control the temperature within the compartment. Accordingly, the food and beverages stored in the cooling compartment may be cooled.

The galley cooling unit includes a heat exchanger to remove heat from within the compartment. For example, hot circuit air flows across an outer surface of tubes containing a cooled liquid coolant. Conventional heat exchangers, such as a liquid-to-air heat exchanger, include one or more cooling tubes to flow liquid therethrough. Heat from within the compartment may be transferred to the liquid flowing through the cooling tubes. The heat of the liquid is ultimately removed and rejected from the aircraft using an additional fluid conditioning system. The shape of the cooling tube may control the amount of heat removed from the liquid, i.e., the heat transfer rate, and the fluid pressure drop across the heat exchanger.

SUMMARY

According to one embodiment of the present inventive concept, a channel tube includes a body having first and second surfaces extending between first and second opposing ends to define a tube width. The first and second surfaces are separated from each other by a distance defining a tube height. A plurality of ports extend through the body and between the first and second surfaces to define a fluid path extending in a direction of the tube width. Each port defines a plurality of walls and a plurality of ribs having a thermal conductive surface to transfer heat therethrough. A first wall extends in a direction of the tube width. The second wall extends in a direction of the tube width and is disposed opposite the first wall. At least one rib is integrally formed between the first and second walls and extends perpendicular thereto.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter which is regarded as the inventive concept is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The forgoing and other features of the inventive concept are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a plan view of a heat exchanger according to an embodiment;

FIG. 2 is an exploded view of the heat exchanger illustrated in FIG. 21; and

FIGS. 3 and 4 are a cross-sectional view of a channel tube according to at least one embodiment.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a heat exchanger assembly 100 is illustrated according to an embodiment. The heat exchanger assembly 100 includes inlet 102 that receives a liquid coolant and an outlet 104 that outputs heated liquid. The core 106 includes a tube assembly 108 defining a liquid circuit. The tube assembly 108 comprises a plurality of layers 110. According to at least one embodiment illustrated in FIG. 2, the tube assembly 108 has twenty-eight layers 110. Each layer 110 comprises a plurality of channel tubes 112. In at least one embodiment, each 110 layer includes three channel tubes 112. One or more of channel tubes 112 may include a plurality of ports 114 that form a fluid path extending along the width of the channel tube 112, as discussed in greater detail below. An air fin 116 may be interposed between each layer 110 to promote the transfer of heat to the liquid flowing through the channel tubes 112.

The channel tubes 112 deliver the liquid coolant from the inlet 102 to the outlet 104. The liquid coolant may comprise a mixture of approximately 60 percent (%) of propylene glycol and 40% water. Air may interact with the heat exchanger assembly 100 through air fin 116 such that heat is transferred from the air to the liquid coolant, thereby cooling the air. The heated liquid flows through the channel tubes 112 undergoing three passes in a cross-counter flow configuration in the process before exiting through outlet 104. Heat may be removed from the liquid cooling loop by downstream equipment.

Referring now to FIGS. 3 and 4, a cross-sectional view of a channel tube 112 is illustrated according to an embodiment. The channel tube 112 includes a body having a first surface, e.g., a top surface 118, and a second surface, e.g., a bottom surface 120. The top and bottom surfaces 118, 120 extend between first and second opposing ends 122, 124 to define a tube width. In at least one embodiment the channel tube has a tube width ranging from approximately 0.995 inches (approximately 2.527 centimeters) to approximately 1.003 inches (approximately 2.548 cm), a tube height (HT_(TUBE)) ranging from approximately 0.125 inches (approximately 0.318 cm) to 0.130 inches (approximately 0.330 cm), and a tube length (L_(TUBE)) ranging from approximately 14.0 inches (approximately 35.56 cm) to approximately 15.0 inches (approximately 38.1 cm). The body of the channel tube 112 is formed integrally from a single thermal conductive material including, but not limited to, 31104 aluminum, and may be formed, for example, using an extrusion process. The first and second ends 122, 124 may include a radius of curvature that ultimately forms a curved nose portion 126. The curved portion 126 extends radially from the body of the channel tube 112 to support and protect the channel tube ends 122, 124 from exterior contact, and while also absorbing fluid pressure exerted on the ends by flowing liquid. The curved nose portion may have a width (W_(END)) of approximately 0.020 inches (approximately 0.051 cm).

The plurality of ports 114 are formed through the body of the channel tube 112 and between the top and bottom surfaces 116,118. Each port 114 extends along the width of the channel tube 112 to convey liquid between the inlet 102 and the outlet 104 of the heat exchanger 100. In one embodiment, the ports 114 are approximately square-shaped. In at least one embodiment, the corners of the ports 114 may be curved to form a square with rounded corners. Alternatively, the ports 114 are rectangular-shaped to define a port height-to-port width ratio. The port height-to-port width ratio may be expressed as port height/port width=ratio. In at least one embodiment, the port height-to-port width ratio is expressed as 0.100 inches/0.0594 inches=1.6835 inches).

In at least one embodiment, the curved ends 122, 124 may define an adjacent port 114 having a semi-circular shape. The width of the semi-circular-shaped end ports (W_(SEMICIRC)) are approximately 0.0594 inch (0.150876 cm). The end ports have a radius of curvature.

Each port 114 defines a first wall, e.g., a top wall 128, a second wall, e.g. a bottom wall 130, and at least one rib, e.g., a center rib 132. The center rib 132 is formed between each adjacent port 114 and extends between the top and bottom walls 128,130. The top and bottom walls 128, 130 have a height (HT_(TOP), HT_(BOTTOM)) of approximately 0.014 inches (approximately 0.036 cm). In at least one embodiment, the center rib 132 has a width (W_(CENTER)) of approximately 0.010 inches (approximately 0.0254 cm). The center rib 132 is not limited to the aforementioned width, and may have a width ranging from approximately 0.0085 inches (approximately 0.0216 cm) to approximately 0.0115 inches (approximately 0.0292 cm). The top wall 128, bottom wall 130, and center rib 132 are formed integrally to one another. Accordingly, dimensions of the walls and ribs define the overall thickness of each port 114. The number of walls and ribs, width of the port, height of the port, rib thickness, wall thickness, tube material controls the rate of heat transferred to the liquid from the air circuit of the heat exchanger. That is, the rate at which heat is added to the liquid flowing at a set flow rate may be controlled by varying each of the described tube dimensions (rib thickness, wall thickness, tube width, number of ports, port width, port height) independent of modifications to the parameters on the air circuit of the heat exchanger. Accordingly, the channel tube 112 may be sized to meet system performance and pressure drop requirements. In at least one embodiment, the ports 114 have a width (W_(PORT)) of approximately 0.0594 inches (approximately 0.150876 cm+/−tolerances) and a height (HT_(PORT)) of approximately 0.100 inches (approximately 0.254 cm+/−tolerances).

The plurality of walls and ribs provide a heat transfer surface, which contacts the liquid flowing through the ports 114. Accordingly, heat is transferred from the liquid through the walls and ribs and out of the channel tubes 112. The rate of heat transfer from the channel tube 112 and the pressure realized by the heat exchanger 100 may be controlled based on the number of ports 114. Reducing the number of ports 114 (e.g., providing 10 ports) reduces the secondary heat transfer area of each tube 112 and decreases the fluid pressure drop, while increasing the number of ports 114, (e.g., providing 18 ports) increases the secondary heat transfer area and increases the fluid pressure drop. Therefore, the heat transfer primary and secondary surface area and fluid pressure drop provided by the channel tube 112 may be controlled based on the number of ports 114 and the design of the corresponding ribs and wall thicknesses, number of ports, the port height, and the port width.

While various embodiments of the inventive concept had been described, it will be understood that those skilled in the art, both now and in the future, may make various modifications to the embodiments which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. 

1. A channel tube included in a heat exchanger, comprising: a body including first and second surfaces extending between first and second opposing ends to define a tube width, outer surfaces of the first and second surfaces separated from each other by a distance defining a tube height; and a plurality of ports extending through the body and between the first and second surfaces to define a fluid path extending in a direction of the tube width, each port defining a plurality of walls and a plurality ribs having a thermal conductive surface to transfer heat therethrough, the plurality of ribs comprising: a first wall extending in a direction of the tube width; a second wall extending in a direction of the tube width, the second rib wall disposed opposite the first wall; and at least one rib integrally formed between the first and second walls and extending perpendicular thereto.
 2. The channel tube of claim 1, wherein the first wall, the second wall and the at least one rib are formed integrally to one another and define a port thickness that determines a heat transfer rate of liquid flowing through the port.
 3. The channel tube of claim 2, wherein the first and second ends include a curved portion extending radially from the body of the tube.
 4. The channel tube of claim 3, wherein the body consists of fourteen ports.
 5. The channel tube of claim 4, where the ports are rectangular-shaped to define a port height-to-port width ratio.
 6. The channel tube of claim 5, wherein the at least one rib has a width of 0.010 inches.
 7. The channel tube of claim 6, wherein the first and second walls have width of 0.014 inches.
 8. The channel tube of claim 7, wherein the port has height of 0.100 inches and a width of 0.0594 inches.
 9. The channel tube of claim 8, wherein the tube height is 0.128 inches.
 10. The channel tube of claim 9, wherein the body, the first and second walls and the at least one rib are integrally formed from a thermal conductive material.
 11. The channel tube of claim 10, wherein the thermal conductive material is aluminum.
 12. The channel tube of claim 3, wherein the width of the curved portion is 0.020 inches. 